Pump jack



April 9, 1940.

J. LUNDGREN I PUMP JACK iled Dec. 15, 1938 Ji ly/ 2 Sheets-Sheet 1 J03 luzzdgrm April 9, 1940. J. LUNDGREN PUMP JACK Filed Dec. 15, 1938 2 Sheets-Sheet 2 gvwc/wfo'b John 1 ufldgren iii Patented Apr. 9, 1940 UNITED STATES" PATENT OFFICE" I 2,196,774. PUMP 11101:

John Lundgren, Askov, Minn. Application December 15, 1938, Serial No. 245,977

6 Claims.

This invention relates to an improved pump jack adapted to be adjustably connected to a pump rod and capable of being driven by a relatively small high speed motor to impart a reciprocating motion to the pump rod.

More particularly it is an aim of this invention to provide a pump jack for reciprocating a pump rod, adapted to be driven by a relatively small electric or gasoline motor and provided with reduction gearing means including an eccentric for actuating a lever for imparting a reciprocating motion tothe pump rod, said device forming an improved transmission for connecting the driven shaft of a high speed motor to a reciprocating pump rod. 7

More particularly, it is an object of this invention to provide a pump jack adapted to be driven by a light high speed motor for reciprocating a vertically disposed pump rod having means whereby the load on the motor will be maintained substantially uniform throughout the stroke of the rod so that the device may be actuated at an even uniform speed. I

It is a further aim of theinvention to provide a pump jack including an 'eccentrically actuated rocking lever adapted to reciprocate a pump rod and actuated by reduction gear means connected to the driven shaft of a high speed motor, and spring counterbalancing means connected to said lever for urging the lever upwardly and for resisting its downward movement to counterbalance the weight of the pump rod to thereby exert a uniform load on the motor.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, which illustrates; preferred embodiment thereof, and wherein:

Figure 1 is a side elevational viewshowing the pump jack connected to a motor and to a pum rod and pump casing,

Figure 2 is a top plan view of the same,

Figure 3 is an end view in elevation of the same,

Figure 4 is a longitudinal vertical sectional view partly in elevation of the pump jack,

Figure 5 is a vertical sectional view taken along the line 55 of Figure 4, I

Figure 6 is a horizontal sectional view taken along the line 6-6 of Figure 4, and

Figure 7 is a sectional view taken along the line 'l-'! of Figure 4.

Referring more particularly to the drawings, wherein like reference characters designate like or corresponding parts throughout the different views, It) designates generallyacasing or housing by means of the anti-friction bearing l1.

in which the pump jack mechanism of this invention is adapted to be enclosed, and which is provided at oneend with'the supporting leg or legs I I. The casing Ill at its opposite end is provided with a vertically disposed portion I2 which is semicircular in cross section and which is adapted to engage a portion of the upper end of a conventional pump casing l3 and to be secured thereto by means of the clamping brackets [4 so that the pump casing l3 co-acts with the leg I I in supporting the casing II).

A thrust bearing member l5 extends upwardly from the bottom of the casing [0 to journal oneend of a shaft l6 which extends outwardly through the first mentioned end of the casing and which is journaled adjacent'its opposite end The last mentioned end of the shaft I6 is connected by means of the universal joint [8 to the driven shaft IQ of a motor, designated 20. The :motor 20 has been shown as a conventional electric motor but a gasoline engine could be used instead or the shaft l9 could be driven from any other suitable source of power desired.

Mounted on and keyed to shaft I6 between the bearings l5 and I1, is a worm 2| thethreads of which are adapted to mesh with a worm wheel 22 which is journaled in one side of the casing.-

I, as best seen in Figure 6, by means of the 1' bearing 23, shaft 24 and the anti-friction bearing- 25 carried by the worm wheel 22.

- A lever, designated 26 is pivotally mounted at one of its ends 2l on a bolt 28 which is mounted in the same side of the casing Hl as the shaft from the axis of the wheel to form an eccentric.

Stud 3! is provided with the nut and washer 32 for removably retaining the stud in engagement with the slot 31!. It will thus be seen, that when the wheel 22 revolves stud 3| will slide relatively to 'slot 39 to cause the lever 26 to swing through a vertical arc.

The opposite end 33 of the lever 26 is disposed adjacent to' the semi-circular portion l2 and has a fastening 34 extending .therethrough and adapted to loosely engage the slots 35 which are formed longitudinally of the intermediate portion of the fork or V-shaped members 36.-

The intermediate portions of the two corresponding V-shaped members 36 are disposed on opposite sides of the end 33 and have their corresponding forked ends 31 bowed outwardly to extend around the inner side of the portion I2, as best seen in Figure 6. The free ends of each of the fork shaped members 36 are bent to lie in a plane substantially parallel to the intermediate portions of said members and are adapted to be fixed to the slides 38 by means of the fastenings 39.

Slides 38 are reciprocally mounted in the guideways 39 formed in the sides of the casing l and on opposite sides of the portion l2. The guideways lfi open outwardly of the top of the casing it so that the slides 38, when in a fully retracted position, as seen in Figures 1 and 4, project above the top of the casing ill to be secured to the lower ends of the bars M which extend upwardly therefrom and which are provided with the cor-' responding spaced openings 42 for adjustably positioning a brace l3, as seen in Figures 2 and 3, therebetween. Brace 43, which extends between the bars ii and is mounted thereby, is disposed above and substantially across the center of the pump casing l3 and is provided, intermediate of its ends, with a clamping bracket 3d adapted to be clamped to a pump rod 45 which is disposed in the pump casing l3 for connecting i to the slides 38. contractile coil spring 46 is connected at one of its ends at M to the lever 26 adjacent the remote end of the slot 35, and has its opposite rod end extending upwardly through an opening 48.

in the top of the casing ill. A cylinder $9 is mounted on the top of casing It and has its bore in alinernent with opening 48 to receive the end 5% of the spring 45 which is connected to an eyebolt 5! which extends upwardly through a disk 52, mounted on the top of the cylinder 49. A nut 53 is connected to the threaded end of the eyebolt iii to rest against the top of the disk 52 to form therewith an abutment for the end 50 of the spring 46, said nut 53 being adjustable to adjust the tension of spring 66.

An arm 5 is fixed at one of its ends to the lever 28 adjacent the end 21 and depends downwardly therefrom and is connected at its free ';end to one end of a contractile coil spring 55 the opposite end of which is connected to a hook 56 mounted in portion ii of easing ID to retain spring 55 under tension.

The top of the casing Ii) is also preferably provided with an opening 5'! adapted to be normally closed by a plug 58 by means of which casing Ill may be partially filled with oil, designated 59 or other suitable lubricant for lubricating the working parts disposed within the casing. The side 6% of casing ill, opposite to that to which worm wheel 22 and lever 26 are mounted, is preferably made removable so that access may be had to the interior of the casing for adjusting or replacing the movable parts contained therein, and is preferably held in place by means of the fastenings ti and may be provided with sealing gaskets, not shown, or other suitable means to make the casing Ell liquid tight in its lower portion.

From the foregoing it will be seen that the motor 2t may be operated to drive shaft l9 which in turn drives shaft l6 and the worm 2i con-- nected thereto. Worm 2| is adapted to be driven at a relatively high rate of speed to revolve the worm wheel 22 at a reduced speed. Worm wheel 22, as heretofore explained, ,actuates the lever it to swing it in a vertical arc by means of the stud and slot connection 3| and 30, respectively.

The free end 33 of the lever is connected by means of the members 36 to the slides 38 so that slides 38 are vertically reciprocated by the swinging movement of lever 26 to reciprocate pump rod 45 in its usual way for pumping a liquid upwardly through pump casing 13 in the conventional manner. Lever 26 is loosely connected to the members 36 by means of the slots 35 so that its end 36 may slide relatively to the members 36 as it swings through its are above and below the horizontal plane of its pivoted end 21. In order to prevent an uneven load on the motor 29 springs 46 and 55 are provided which combine to urge the lever 26 upwardly and which resist its downward movement to thereby counterbalance the weight of the pump rod 45 and the column of liquid being raised thereby so that an even load will be maintained on the motor during the complete revolution of the worm wheel 22 to thereby prevent excess strain on the motor and an uneven operating speed. Furthermore, by providing the springs 46 and 55 it is possible to use a small low horse power high speed motor for performing the pumping operation. The spring 56 imparts an upward pull to the lever 26 while the spring 55 urges the arm 54 forwardly and upwardly of the end 21 of the lever to thereby cooperate with the spring $6 in raising the lever and functions particularly to urge the lever 26 upwardly when it is at the lowest point of its arc and when the stud 3i vis directly beneaththe axis of the gear wheel 22, at which point the spring M5 is substantially inoperable as it is pulling against a dead center position of the lever 26 so that the spring 55 bears the burden with the motor of starting the lever 25 and the pump rod 45 on its upward movement.

Various modifications and changes in the construction and arrangement of the parts forming the invention are contemplated and may obviously be resorted to, and the right is therefore expressly reserved to make such variations and changes as do not depart from the spirit and scope of the invention as hereinafter defined by the appended claims.

I claim as my invention:

1. A pump jack comprising clamping means adapted to beadjustably connected to a pump rod, slides connected to said clamping means, guideways for said slides, a casing, a lever pivotally connected at one end to said casing, fork shaped members secured to said slides and pivotally and slidably connected to the free end of said lever, a worm wheel eccentrically connected to the intermediate portion of said lever, said worm wheel being journaled in said casing, and a worm in mesh with said worm wheel and keyed to a driven shaft journaled in said casing for actuating said lever for reciprocating said slides and the pump rod connected thereto.

2. A device as in claim 1, and a plurality of contractile coil springs connected to said lever and casing and disposed substantially at right angles to each other for urging said lever upwardly to counterbalance the weight of the pump rod.

3. A pump jack comprising a casing adapted to contain a lubricant, a driven shaft journaled in the bottom part of said casing, a worm keyed to said shaft, a worm wheel provided with a shaft journaled in one side of, said casing, said worm wheel having an eccentrically disposed stud projecting from one side thereof, a lever pivotally connected at one endto said casing, said lever having a longitudinal slot intermediate of its ends slidably connected to said stud, guideways formed in saideasing, slides mounted in said guideways and provided with clamping means adapted to be adjustably connected to a pump rod, fork shaped members having their ends connected to said slides and their intermediate portions slidably and pivotally connected to the free end of said lever for reciprocating said slides when said lever is actuated by operation of the worm and worm wheel, and an adjustable contractile spring connected to said casing and to the lever, between the slot and its free end, for urgingsaid lever upwardly to counterbalance the weight of the piston rod.

4. A device as in claim 3, an arm secured to and depending from said lever adjacent its pivoted end, and a contractile spring connected to the free end of said arm and to said casing, said last 5. A pump jack comprising a casing having a vertically disposed portion, semi-circular in cross section, at one end thereof adapted to engage the I upper end of a pump casing, vertically disposed guideways formed in said casing at the sides of said semi-circular portion and opening outwardly of the top thereof, bars slidably mounted in said guideways and projecting upwardly from said casing, adjustable clamping means carried by lever, and means eccentrically connected to the intermediate portion of said lever for actuating it to impart a reciprocating motion to said bars. 6. A device as in claim 5, and contractile coil springs disposed at right angles to each other.

and connected to said leverand casing for urging said lever upwardly to counterbalance the weight of the pump rod.

JOHN LUNDGREN. 

